Steam generator



April 28, 1942. 1 H. cusHMAN STEAM'QENERATOR Filed Feb. s, 1941 Patented Apr. 28, 1942 UNITE-D STATES PATENT OFFICE STEAM GENERATOR Lee H. Cushman, Hamilton, Mass., assigner to United Shoe Machinery Corporation, Flemington, N. J., a corporation of New Jersey Application February 3, 1941, Serial No. 377,101

(Cl. 21S- 38) 4 Claims.

This invention relates to steam generators of the flash type, and to the problem of controlling the delivery thereto of the water to be converted into steam.

An object of the invention is to provide an apparatus in which steam will be generated only as needed to maintain a limited supply, and in which the water in the boiler will be -automatically replenished only as needed to replenish the supply of steam.

Another object is to maintain a predetermined pressure of the steam in the boiler during those intervals when the outlet of steam is temporarily stopped, as by closing a throttle-valve and to restore the same pressure automatically after every interruption in the discharge of steam from the boiler.

The invention is herein illustrated as embodied in an apparatus to be used in the manufacture of shoes, but it is to be understood that the use to which the steam is put is not of primary importance, and that the principles of the invention may be utilized in other situations. It is also to be understood that the accompanying rawing is elementary rather than a literal picture of actual structure, the better to illustrate the princi-ples involved.

The results above mentioned are obtained by organizing a pressure-sustaining boiler, a flasher and a feed-water to generate steam only when the steam throttle-valve is open and the pressure of steam in the boiler is thereby reduced below a predetermined degree, and to employ steam-pressure in excess of feed-water pressure to arrest the generation of steam by arresting the influx of water. To obtain such control from the steam-pressure the water is supplied to the boiler without being flashed until enough water has been accumulated therein to raise the water-level to the bottom of the flasher. The heating capacity of the flasher and the area of the steam space of the boiler are so proportioned as to maintain a static steam pressure superior to the feed-water pressure so long as the outlet of steam is stopped. Consequently, steam will be generated only when the throttle-valve is open, but if the latter 'be closed steam already accumulated in the boiler will be maintained at a constant pressure so long as the flasher remains hot.

Referring to the drawing,

Fig. l is an elevation, partly in section, of an apparatus for treating shoes with hot air and steam, the steam generator ,and the feed-water thereof embodying the novel features of the invention;

Fig. 2 is a bottomplan view of the nozzles from which the hot air and steam are emitted;

Fig. 3 is an elevation projected fromFig. 2; and

Fig. 4 is a vertical section of the lower portion of the steam generator.' (See line IV-IV in Fig. l.)

Referring to the drawing, the boiler comprises a shell I0 forming :a `pressure-sustaining chamber II and containing a asher having a constant output of heat. The ilasher comprises a series oi' brass tubes I2 each containing an electric heating unit. These tubes are welded to the shell I0 and are arranged at a common level in the chamber II, their major dimensions being horizontal. The shell I0 is provided with a water inlet I3 below the ilasher and with a steam outlet I4 above the flasher. A `pipe I5 provided with a manually operable throttle-valve I6 is arranged to conduct the steam from the outlet I4 to a point of delivery.

Water under a head of pressure is conducted from a source of supply to the inlet I3 by a pipe I'I. This pipe is provided with a shutol valve 9 which may be left open except when the flasher is out of operation. When constant water pressure is desired the water may be supplied by a barometrie feeder comprising an inverted container I8 and a sealing bowl IS. These elements will maintain the water in the bowl at a constant level indicated lat 20 which may be at any desired distance above the level of the bottoms of the flasher tubes I2 in the boiler. The latter level is indicated at 2 I.

When starting the apparatus in operation the shutoff valve 9 should remain closed until the asher is het enough to operate as such. Then the valve 9 may be opened. The w-ater in the chamber II will then rise until it touches the tubes I2. The immediate result of such contact will be a steam-pressure greater than the .pressure of the water due to the head Zil-ZI. This development of steam-pressure is so rapid that the water in the boiler will never rise perceptibly above the level 2l. Moreover, the steam-pressure will depress the water in the boiler below the level 2I. Cnce the chamber II has been supplied with steam, the throttle-valve IB may be adjusted according to the demand for steam. When the throttle-valve is closed without turning 01T the current for the heating units the flasher will maintain pressure of the accumulated steam without generating more steam.

The drawing .also includes means for utilizing the steam to eliminate wrinkles from the uppers of completely fabricated leather shoes. Accordingly, the pipe I5 terminates in an annular nozzle 25 that surrounds a nozzle 26. Air is supplied by a blower 21 to the nozzle 26 to be emitted on the shoe. The air travels through a heater 24 by Which it is heated to a temperature of about 450 F. A series of small ports 29 in the bottom of the annular nozzle 25 emit jets of steam lat the same time, the ycentral jet of hot air serving to prevent condensation of the steam on the shoe. A coil 28 is formed in the pipe l5 to reduce the temperature of the steam.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

l. A steam-generating apparatus comprising a vboiler shell forming a pressure-sustaining chamber, a flasher located in the steam-space of said chamber, said chamber having a water-inlet below and a steam-outlet above said Ilasher, a throttle-valve arranged to arrest the escape of steam from said chamber, and means by which Water is supplied through said inlet to replenish the Water in said chamber to the level of the bottom of said flasher.

2. A steam-generating apparatus as speciled in claim 1 in which the heating surface and capacity of said flasher and the steam-space of said chamber are so proportioned that the static steam-pressure, when said outlet is stopped, will maintain the water-level below the bottom of the flasher.

3. A steam-generating apparatus comprising a boiler shell forming a pressure-sustaining chamber, a flasher located in the steam space of said chamber, said chamber having a Water-inlet below and a steam-outlet above said flasher, a throttie-valve controlling the escape of steam from said chamber, and means by which Water at la constant pressure is supplied through said inlet to replenish the water in said chamber to the level of the bottom of said Ilasher.

4. A steam-generating apparatus comprising `a boiler shell forming a pressure-sustaining chamber, a Ilasher located in the steam space of said chamber, said chamber having a water-inlet below and a steam-outlet above said flasher, a barometric Water--feeder the water-level of which is above the level of the bottom of said flasher, and a conduit through which water is conducted from said feeder to the Water-inlet of said chamber.

LEE H. CUSHMAN. 

